| 摘要 |
PURPOSE:To properly control the injection of Fe ion and to stably maintain an Fe-base protective film when the corrosion of a heat exchanger using sea water is prevented with the protective film formed by injecting Fe ion, by placing detection electrodes at the water chamber, the cooling tube, etc. of the exchanger and a path for taking in sea water. CONSTITUTION:Sea water is used as a heat medium in a heat exchanger provided with a cooling tube made of a copper alloy. In order to prevent the corrosion of the water chamber, the tube sheets, the cooling tube, etc. of the exchanger due to sea water, an aqueous FeSO4 soln. is injected to form an Fe-base protective film on the inside of the exchanger. Detection electrodes 2, 3 are placed at the water chamber 5, the tube sheets and the cooling tube of the exchanger and a section 9 for taking in fresh sea water contg. no FeSO4 to detect the state of the formed protective film from the difference between the detected outputs of film resistance values. In accordance with the result, the FeSO4 soln. is injected from an injector 7 to stably maintain the protective film and to prevent corrosion due to sea water. |
